JP5118913B2 - Power supply system, electric vehicle equipped with the same, and control method of power supply system - Google Patents

Abstract

Converters (8-1, 8-2) are configured to operate in a normal operation to convert the electric power that is input/output to/from secondary batteries (6-1, 6-2) bidirectionally to direct current voltage. In a predetermined mode allowing the secondary batteries (6-1,6-2) to be charged, at least one of the converters (8-1, 8-2) does not perform a switching operation and holds on an upper arm element (Q1B, Q2B) to avoid a switching loss in charging the secondary batteries (6-1,6-2). An electric power loss caused at the converters in charging the secondary batteries can be reduced, and charging efficiency can be enhanced.

Description

  The present invention relates to a power supply system, an electric vehicle equipped with the same, and a control method for the power supply system, and more specifically, mounted on an electric vehicle capable of generating a driving force using electric power stored in a power storage device. The present invention relates to charging control of a power storage device in a power supply system.

  In recent years, in an electric vehicle equipped with an electric motor as a driving force source for driving such as a hybrid vehicle or an electric vehicle, the capacity of the power storage mechanism has been increased in order to improve the driving performance such as acceleration performance and driving distance. Is progressing. As a technique for increasing the capacity of the power storage mechanism, a configuration in which a plurality of power storage devices are arranged in parallel has been proposed.

  For example, Japanese Patent Laid-Open No. 2003-209969 (Patent Document 1) includes a plurality of power supply stages configured by a set of a low-voltage battery and a converter, and configures a power supply control system for a motor that generates vehicle driving force Is disclosed. In particular, Patent Document 1 discloses a control configuration that balances the battery charge rate between batteries by performing individual current limit control for each of these power supply stages.

Japanese Patent Laid-Open No. 2003-134606 (Patent Document 2) discloses a configuration in which a motor unit is driven and controlled by a combination of a single battery and a buck-boost converter. It is disclosed that a switch is steadily turned on to ensure power supply to an auxiliary machine with power supplied from an electric motor unit.
JP 2003-209969 A JP 2003-134606 A

  In an electric vehicle such as a hybrid vehicle or an electric vehicle, a method of improving fuel consumption is generally used by using the electric power generated by the motor during regenerative braking as the charging power of the power storage device during vehicle operation.

  Furthermore, in recent years, a configuration has been proposed in which an electric vehicle is charged by an external power source during parking after operation is stopped. Such charging by an external power source is performed at a nighttime or the like, which requires a relatively long time, and there is a concern that the efficiency during charging becomes a problem.

  In particular, in the power supply system configuration that performs power conversion between the power storage device and the electric motor via the converter, each power storage device is charged via the converter even when charging by an external power source. Increased efficiency is required.

  In particular, as in Patent Document 1, in a power supply system in which a plurality of power storage devices and converters are arranged in parallel, it is necessary to prevent the efficiency of charging by an external power source from being reduced due to loss in the plurality of converters. is there. However, Patent Documents 1 and 2 do not mention how to control the converter in the power supply system as described above when charging the power storage device, particularly when charging for a long time with an external power supply.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a power supply system mounted on an electric vehicle in which a plurality of sets of power storage devices and converters are arranged in parallel. Is to reduce the power loss in the converter during charging of the power storage device and improve the charging efficiency.

  A power supply system according to the present invention is a power supply system mounted on an electric vehicle capable of generating a driving force using electric power on a power line, and includes a plurality of chargeable / dischargeable power storage devices, a power line, and a plurality of power storage devices. And a plurality of converters connected to each other and a control device. Each converter includes a plurality of power semiconductor switching elements so as to perform bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and a power line. The plurality of power semiconductor switching elements include a first switching element electrically connected between the power line and the corresponding power storage device. The control device controls on and off of each power semiconductor switching element of each converter. Then, the control device selects at least a part of the plurality of power storage devices as a charging target and is selected as a charging target in a predetermined mode in which the plurality of power storage devices are charged with power supplied to the power line. In the converter corresponding to the power storage device, the first switching element is fixed on, while the converter corresponding to the remaining power storage device other than the charging target turns off the first switching element, thereby Charge the device.

  According to the above power supply system, in the converter corresponding to the power storage device selected as the charging target in the predetermined mode, the switching element (first switching element) is fixed to ON, and switching loss due to ON / OFF operation (switching operation) A plurality of power storage devices can be charged using the electric power on the power line without generating. For this reason, by applying the predetermined mode to the external charging mode or the like over a relatively long time, the power loss in the converter can be reduced and the charging efficiency of the power storage device can be increased.

  Preferably, in the predetermined mode, the control device selects each of the plurality of power storage devices as a charging target in parallel, and fixes the first switching element on in each converter.

  With such a configuration, each power storage device can be charged in parallel without causing a switching loss in each converter.

  More preferably, in the predetermined mode, the control device sets the voltage of the power line to the output voltage of the plurality of power storage devices by at least one on / off control of the plurality of power semiconductor switching elements by at least one of the plurality of converters. After control equivalent to the highest voltage among them, the first switching element is turned on in each converter.

  With such a configuration, when the first switching element of each converter is turned on to start charging, it is possible to prevent an excessive inrush current from flowing from the power line to each power storage device.

  Alternatively, more preferably, the control device charges / discharges the plurality of power storage devices so that the charge level difference is equal to or less than a predetermined value when a difference in charge level between the plurality of power storage devices is greater than a predetermined value at the start of the predetermined mode After the adjustment control for controlling the plurality of converters is executed, the first switching element is turned on in each converter.

  With such a configuration, when the first switching element of each converter is turned on to start charging, it is possible to prevent a short-circuit current due to a charge level difference between power storage devices.

  Preferably, the power supply system further includes a plurality of opening / closing devices respectively provided between the plurality of converters and the plurality of power storage devices. Then, in the predetermined mode, the control device sequentially selects a part of the plurality of power storage devices as a charging target, and sets a first switching element in a converter corresponding to the power storage device selected as the charging target. While fixing to ON, the 1st switching element and switchgear corresponding to the remaining electrical storage apparatuses other than charging object are turned off.

  With this configuration, a plurality of power storage devices can be sequentially selected as charging targets, and the power storage devices selected as charging targets can be charged without causing a switching loss in a corresponding converter. . Furthermore, by turning off the switchgear device, it is possible to physically prevent a short-circuit current from being generated between the charging target and non-charging target power storage devices when the first switching element corresponding to the charging target is turned on.

  A power supply system according to another aspect of the present invention is a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line, and includes a plurality of chargeable / dischargeable power storage devices, a power line, and a plurality of power lines. A plurality of converters connected to each of the power storage devices, and a control device. Each converter includes a plurality of power semiconductor switching elements so as to perform bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and a power line. The plurality of power semiconductor switching elements include a first switching element electrically connected between the power line and the corresponding power storage device. The control device controls on and off of each power semiconductor switching element of each converter. Then, in a predetermined mode in which the plurality of power storage devices are charged with the power supplied to the power line, the control device outputs a charging current of the corresponding power storage device in a converter corresponding to a part of the plurality of power storage devices. At least one of the plurality of power semiconductor switching elements is turned on / off so as to control to the target current, while the first switching element is fixed on in the converter corresponding to the remaining power storage devices other than some power storage devices. By doing so, the plurality of power storage devices are charged.

  In the power supply system, in a predetermined mode, only a part of the plurality of converters is switched to control the charging current, while the remaining converters are turned on with the switching element (first switching element) turned on. A plurality of power storage devices can be charged in parallel using power on the power line without generating a switching loss. Thereby, compared with the case where it charges by performing switching operation | movement of each converter in parallel, the power loss in a converter can be suppressed. As a result, by applying the predetermined mode to the external charging mode or the like over a relatively long time, the power loss in the converter can be reduced and the charging efficiency of the power storage device can be increased.

  Preferably, the control device sets the target current according to a difference in charge level among the plurality of power storage devices.

  With such a configuration, it is possible to charge a plurality of power storage devices equally and in parallel so as to eliminate a difference in charge level between the plurality of power storage devices.

  A power supply system according to still another aspect of the present invention is a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line, and a plurality of chargeable / dischargeable power storage devices, a power line, A plurality of converters connected to the plurality of power storage devices, respectively, and a control device. Each converter includes a plurality of power semiconductor switching elements so as to perform bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and a power line. The plurality of power semiconductor switching elements include a first switching element electrically connected between the power line and the corresponding power storage device. The control device controls on and off of each power semiconductor switching element of each converter. Then, the control device sequentially selects some of the plurality of power storage devices as charging targets and is selected as the charging target in a predetermined mode in which the plurality of power storage devices are charged with the power supplied to the power line. In the converter corresponding to the power storage device, in the converter corresponding to the remaining power storage device other than the charging target while turning on / off at least one of the plurality of power semiconductor switching elements so as to control the voltage of the power line to the target voltage The plurality of power storage devices are charged by turning off the first switching element.

  In the power supply system described above, in a predetermined mode, a plurality of power storage devices are charged using power on the power line by switching only some converters corresponding to the power storage devices selected as charging targets. For this reason, compared with the case where it charges by performing switching operation of each converter in parallel, the power loss in a converter can be controlled. As a result, by applying the predetermined mode to the external charging mode or the like over a relatively long time, the power loss in the converter can be reduced and the charging efficiency of the power storage device can be increased.

Preferably, the control device sets the target voltage to be higher than the highest voltage among the output voltages of the plurality of power storage devices.
With such a structure, it is possible to prevent generation of a current flowing from the non-charge target power storage device to the charge target power storage device.

  Preferably, the power supply system further includes a plurality of opening and closing devices respectively provided between the plurality of converters and the plurality of power storage devices, and the control device corresponds to each power storage device other than the charging target in the predetermined mode. Turn off the switchgear.

  With such a configuration, it is possible to physically prevent a current flowing from the non-charge target power storage device to the charge target power storage device.

  More preferably, the control device switches the charging target in response to the charging target power storage device being charged to the target level. Then, the target level is set such that each power storage device is selected as a charging target a plurality of times before being charged to the full charge level.

  With such a configuration, even if the predetermined mode is terminated before all of the plurality of power storage devices reach the full charge level, it is possible to prevent a large difference in the charge level between the power storage devices.

  Preferably, in a predetermined mode, power from an external power source of the electric vehicle is supplied to the power line.

  With such a configuration, when a plurality of power storage devices are charged with power from an external power supply, charging efficiency can be improved by reducing power loss in the plurality of converters.

  An electric vehicle according to the present invention includes any one of the above-described power supply systems, a first AC rotating electric machine including a star-connected first multiphase winding as a stator winding, and a star-connected second. ON / OFF of the second AC rotating electric machine including the multi-phase winding as the stator winding, the first and second inverters, the connector section, and the power semiconductor switching elements of the first and second inverters And an inverter control device for controlling. The first inverter is connected to the first multiphase winding and performs power conversion between the first AC rotating electric machine and the power line. The second inverter is connected to the second multiphase winding and performs power conversion between the second AC rotating electric machine and the power line. In the predetermined mode, the connector section is provided between the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding and the AC power supply outside the electric vehicle. Provided for electrical connection. At least one of the first and second AC rotating electric machines is used to generate a driving force. Then, in the predetermined mode, the inverter control device converts the AC voltage from the AC power source supplied to the first and second neutral points via the connector portion into a DC voltage and outputs it to the power line. Each of the first and second inverters is controlled.

  According to the above electric vehicle, when charging a plurality of power storage devices with electric power from an external power source, the charging efficiency can be improved by reducing power loss in the plurality of converters, and the second driving power generation can be used. Using the first and second AC rotating electric machines and the inverter that controls them, it is possible to convert the power supplied from the external power source into power for charging a plurality of power storage devices without providing new equipment.

  A control method for a power supply system according to the present invention is a control method for a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line. Power storage device, a plurality of converters respectively connected between the power line and the plurality of power storage devices, and a control device. Each converter includes a plurality of power semiconductor switching elements so as to perform bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and a power line. The plurality of power semiconductor switching elements include a first switching element electrically connected between the power line and the corresponding power storage device. The control device controls on and off of each power semiconductor switching element of each converter. The control method includes a step of selecting at least a part of the plurality of power storage devices as a charge target in a predetermined mode in which the plurality of power storage devices are charged with power supplied to the power line, and selecting the charge target In the converter corresponding to the stored power storage device, the first switching element is fixed on, while in the converter corresponding to the remaining power storage device other than the charging target, the charging operation is performed by turning off the first switching element. Performing steps.

  According to the control method of the power supply system described above, in the converter corresponding to the power storage device selected as the charging target in the predetermined mode, the switching element (first switching element) is fixed on, and the on / off operation (switching operation) A plurality of power storage devices can be charged using the power on the power line without causing switching loss due to. For this reason, by applying the predetermined mode to the external charging mode or the like over a relatively long time, the power loss in the converter can be reduced and the charging efficiency of the power storage device can be increased.

  Preferably, in the selecting step, each of the plurality of power storage devices is selected as a charging target in parallel in the predetermined mode. The step of executing the charging operation fixes the first switching element on in each converter.

  By adopting such a control structure, each power storage device can be charged in parallel without causing a switching loss in each converter.

  More preferably, in the control method, prior to the charging operation, the power line voltage is output from the plurality of power storage devices by at least one on / off control of the plurality of power semiconductor switching elements by at least one of the plurality of converters. The method further includes a step of controlling to be equal to the highest voltage of the voltages.

  With such a control structure, it is possible to prevent an excessive inrush current from flowing from the power line to each power storage device when charging is started by turning on the first switching element of each converter.

  Alternatively, more preferably, the control method charges and discharges the plurality of power storage devices so that the charge level difference is equal to or less than a predetermined level when the charge level difference between the plurality of power storage devices is greater than a predetermined value prior to the charging operation. For this purpose, the method further comprises controlling a plurality of converters.

  With such a control structure, when the first switching element of each converter is turned on to start charging, it is possible to prevent a short-circuit current caused by a charge level difference between the power storage devices.

  Preferably, the power supply system further includes a plurality of opening / closing devices respectively provided between the plurality of converters and the plurality of power storage devices. The step of selecting sequentially selects a part of the plurality of power storage devices as a charging target in the predetermined mode, and the step of executing the charging operation is performed on the power storage device selected as the charging target. While the first switching element is fixed on in the corresponding converter, the first switching element and the switching device corresponding to the remaining power storage device other than the charging target are turned off.

  By adopting such a control structure, it is possible to sequentially select a plurality of power storage devices as charging targets and charge the power storage devices selected as charging targets without causing switching loss in a corresponding converter. it can. Furthermore, by turning off the switchgear device, it is possible to physically prevent a short-circuit current from being generated between the charging target and non-charging target power storage devices when the first switching element corresponding to the charging target is turned on.

  A control method for a power supply system according to another aspect of the present invention is a control method for a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line. A plurality of dischargeable power storage devices, a plurality of converters connected between the power line and the plurality of power storage devices, respectively, and a control device. Each converter includes a plurality of power semiconductor switching elements so as to perform bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and a power line. The plurality of power semiconductor switching elements include a first switching element electrically connected between the power line and the corresponding power storage device. The control device controls on and off of each power semiconductor switching element of each converter. Then, in a predetermined mode in which a plurality of power storage devices are charged with the power supplied to the power line, the control method uses a converter corresponding to a part of the plurality of power storage devices to charge current of the corresponding power storage device. At least one of the plurality of power semiconductor switching elements is turned on / off so as to control to the target current, while the first switching element is fixed on in the converter corresponding to the remaining power storage devices other than some power storage devices. To perform a charging operation.

  According to the control method of the power supply system described above, in the predetermined mode, in the predetermined mode, only some of the plurality of converters are switched so as to control the charging current, while the remaining converters have switching elements ( The plurality of power storage devices can be charged in parallel using the power on the power line without fixing the first switching element) and causing a switching loss. Thereby, compared with the case where it charges by performing switching operation | movement of each converter in parallel, the power loss in a converter can be suppressed. As a result, by applying the predetermined mode to the external charging mode or the like over a relatively long time, the power loss in the converter can be reduced and the charging efficiency of the power storage device can be increased.

  Preferably, the control method further includes a step of setting a target current in the charging operation according to a difference in charge level among the plurality of power storage devices.

  By adopting such a control structure, the plurality of power storage devices can be charged equally and in parallel so as to eliminate the difference in charge level between the plurality of power storage devices.

  A control method for a power supply system according to another aspect of the present invention is a control method for a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line. A plurality of dischargeable power storage devices, a plurality of converters connected between the power line and the plurality of power storage devices, respectively, and a control device. Each converter includes a plurality of power semiconductor switching elements so as to perform bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and a power line. The plurality of power semiconductor switching elements include a first switching element electrically connected between the power line and the corresponding power storage device. The control device controls on and off of each power semiconductor switching element of each converter. The control method includes a step of sequentially selecting a part of the plurality of power storage devices as a charge target in a predetermined mode in which the plurality of power storage devices are charged with the power supplied to the power line, and selecting the charge target In the converter corresponding to the stored power storage device, at least one of the plurality of power semiconductor switching elements is turned on / off so as to control the voltage of the power line to the target voltage, while the converter corresponds to the remaining power storage device other than the charging target And performing a charging operation by turning off at least the first switching element.

  According to the control method of the power supply system described above, in a predetermined mode, a plurality of power storage devices are charged using power on the power line by switching only some converters corresponding to the power storage devices selected as charging targets. To do. For this reason, compared with the case where it charges by performing switching operation of each converter in parallel, the power loss in a converter can be controlled. As a result, by applying the predetermined mode to the external charging mode or the like over a relatively long time, the power loss in the converter can be reduced and the charging efficiency of the power storage device can be increased.

  Preferably, in the step of executing the charging operation, the target voltage is set higher than the highest voltage among the output voltages of the plurality of power storage devices.

  With such a control structure, it is possible to prevent the occurrence of current flowing from the non-charge target power storage device to the charge target power storage device.

  Preferably, the power supply system further includes a plurality of opening / closing devices respectively provided between the plurality of converters and the plurality of power storage devices. In the step of executing the charging operation, the opening / closing devices corresponding to the remaining power storage devices are turned off.

  With such a control structure, it is possible to physically prevent the occurrence of current flowing from the non-charge target power storage device to the charge target power storage device.

  More preferably, the control method further includes a step of detecting that the power storage device to be charged has been charged to the target level, and a step of switching the charging target in response to the detection in the detecting step. In the detecting step, the target level is set so that the power storage devices are selected as charging targets a plurality of times before each power storage device is charged to the full charge level.

  By adopting such a control structure, even if the predetermined mode is terminated before all of the plurality of power storage devices reach the full charge level, it is possible to prevent a large difference in the charge level between the power storage devices. .

  Preferably, in a predetermined mode, power from an external power source of the electric vehicle is supplied to the power line.

  Thereby, when charging a plurality of power storage devices with power from an external power supply, charging efficiency can be improved by reducing power loss in the plurality of converters.

  Preferably, the electric vehicle includes a first AC rotating electric machine including a first multiphase winding connected in a star shape as a stator winding, and a second multiphase winding connected in a star shape as a stator. A second AC rotating electric machine including windings, first and second inverters, a connector unit, and an inverter control device for controlling on and off of power semiconductor switching elements of the first and second inverters; Further prepare. The first inverter is connected to the first multiphase winding and performs power conversion between the first AC rotating electric machine and the power line. The second inverter is connected to the second multiphase winding and performs power conversion between the second AC rotating electric machine and the power line. In the predetermined mode, the connector section is provided between the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding and the AC power supply outside the electric vehicle. Provided for electrical connection. At least one of the first and second AC rotating electric machines is used to generate a driving force. Then, in the predetermined mode, the inverter control device converts the AC voltage from the AC power source supplied to the first and second neutral points via the connector portion into a DC voltage and outputs it to the power line. Each of the first and second inverters is controlled.

  Thereby, when charging the plurality of power storage devices of the power supply system with the power from the external power supply, the charging efficiency can be improved by reducing the power loss in the plurality of converters, and the first used for generating the driving force. Using the second AC rotating electric machine and the inverter that controls them, it is possible to convert the power supplied from the external power source into power for charging a plurality of power storage devices without providing new equipment.

  According to the present invention, in a power supply system mounted on an electric vehicle in which a combination of a plurality of power storage devices and converters are arranged in parallel, the power loss in the converter during charging of the power storage device is reduced, and the charging efficiency is improved. Can be improved.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

[Embodiment 1]
(Overall configuration of power supply system)
FIG. 1 is an overall block diagram of an electric vehicle 100 equipped with a power supply system according to an embodiment of the present invention.

  Referring to FIG. 1, electrically powered vehicle 100 includes a power supply system 101 and a driving force generation unit 103. Driving force generation unit 103 includes inverters 30-1 and 30-2, motor generators 34-1 and 34-2, a power transmission mechanism 36, and a drive ECU (Electronic Control Unit) 32.

  Inverters 30-1 and 30-2 are connected in parallel to main positive bus MPL and main negative bus MNL. Inverters 30-1 and 30-2 convert driving power (DC power) supplied from power supply system 101 into AC power and output the AC power to motor generators 34-1 and 34-2, respectively. Inverters 30-1 and 30-2 convert AC power generated by motor generators 34-1 and 34-2 into DC power and output the power to power supply system 101 as regenerative power.

  As will be described later, each of inverters 30-1 and 30-2 is formed of a general three-phase inverter, and performs a switching operation in accordance with drive signals PWM1 and PWM2 from drive ECU 32, respectively, thereby corresponding motor generators. Drive.

  Motor generators 34-1 and 34-2 receive the AC power supplied from inverters 30-1 and 30-2, respectively, and generate rotational driving force. Motor generators 34-1 and 34-2 generate AC power in response to external rotational force. Motor generators 34-1 and 34-2 are each composed of, for example, a three-phase AC rotating electric machine including a rotor in which permanent magnets are embedded. Motor generators 34-1 and 34-2 are connected to power transmission mechanism 36, and a rotational driving force is transmitted to wheels (not shown) via drive shaft 38 further connected to power transmission mechanism 36. .

  When electric vehicle 100 is a hybrid vehicle, motor generators 34-1 and 34-2 are also coupled to an engine (not shown) via power transmission mechanism 36 or drive shaft 38. Control is executed by drive ECU 32 so that the drive force generated by the engine and the drive force generated by motor generators 34-1 and 34-2 have an optimal ratio. Note that either one of the motor generators 34-1 and 34-2 may function exclusively as an electric motor, and the other motor generator may function exclusively as a generator.

  Drive ECU 32 calculates torque target values TR1, TR2 and rotation speed target values MRN1, MRN2 of motor generators 34-1, 34-2 based on detection signals of respective sensors (not shown), travel conditions, accelerator opening, and the like. . In general, torque target values TR1 and TR2 are set to positive values during motoring operation in which motor generators 34-1 and 34-2 generate travel driving force, and torque target values TR1 and TR2 are negative values during regenerative braking. Set to

  Then, drive ECU 32 generates drive signal PWM1 and controls inverter 30-1 so that the generated torque and the rotation speed of motor generator 34-1 become torque target value TR1 and rotation speed target value MRN1, respectively. Drive signal PWM2 is generated to control inverter 30-2 so that the generated torque and the rotational speed of 34-2 become torque target value TR2 and rotational speed target value MRN2, respectively. Further, drive ECU 32 outputs calculated torque target values TR1, TR2 and rotation speed target values MRN1, MRN2 to converter ECU 2 (described later) of power supply system 101.

  Thus, electrically powered vehicle 100 uses the DC power between main positive bus MPL and main negative bus MNL from power supply system 101 to generate travel driving force by at least one of motor generators 34-1 and 34-2. It is configured to be possible.

  On the other hand, power supply system 101 includes power storage devices 6-1 and 6-2, converters 8-1 and 8-2, smoothing capacitor C 1, converter ECU 2, current sensors 10-1 and 10-2, and voltage sensor. 12-1, 12-2, and 18 are included.

  Since power storage devices 6-1 and 6-2 are typically constituted by secondary batteries such as nickel-hydrogen secondary batteries or lithium ion secondary batteries, power storage devices 6-1 and 6-2 are described below. Is also simply referred to as a secondary battery or a battery. However, the point that power storage devices other than the secondary battery, such as an electric double layer capacitor, can be applied instead of the secondary batteries 6-1 and 6-2 will be described in a confirming manner.

  Secondary battery 6-1 is connected to converter 8-1 via positive line PL1 and negative line NL1, and secondary battery 6-2 is connected to converter 8-2 via positive line PL2 and negative line NL2. Is done.

  Converter 8-1 is provided between secondary battery 6-1 and main positive bus MPL and main negative bus MNL, and based on drive signal PWC1 from converter ECU 2, secondary battery 6-1 and main positive bus. Voltage conversion is performed between MPL and main negative bus MNL. Converter 8-2 is provided between secondary battery 6-2 and main positive bus MPL and main negative bus MNL, and based on drive signal PWC2 from converter ECU 2, secondary battery 6-2 and main positive bus. Voltage conversion is performed between MPL and main negative bus MNL.

  Smoothing capacitor C1 is connected between main positive bus MPL and main negative bus MNL, and reduces power fluctuation components included in main positive bus MPL and main negative bus MNL. Voltage sensor 18 detects voltage Vh between main positive bus MPL and main negative bus MNL, and outputs the detected value to converter ECU 2.

  Current sensors 10-1 and 10-2 detect current Ib1 input to and output from secondary battery 6-1 and current Ib2 input to and output from secondary battery 6-2, respectively, The value is output to converter ECU 2 and battery ECU 4. The current sensors 10-1 and 10-2 detect the current (discharge current) output from the corresponding secondary battery as a positive value, and the current (charge current) input to the corresponding secondary battery is negative. Detect as value.

  FIG. 1 shows a case where the current sensors 10-1 and 10-2 detect the currents of the positive lines PL1 and PL2, respectively. However, the current sensors 10-1 and 10-2 are respectively connected to the negative lines. The currents NL1 and NL2 may be detected. Voltage sensors 12-1 and 12-2 detect voltage Vb1 of secondary battery 6-1 and voltage Vb2 of secondary battery 6-2, respectively, and output corresponding detection values to converter ECU 2 and battery ECU 4. The operations of converter ECU 2 and battery ECU 4 will be described in detail later.

FIG. 2 is a circuit diagram showing in detail the configuration of the driving force generator 103 shown in FIG.
Referring to FIG. 2, inverter 30-1 is a general three-phase inverter composed of power semiconductor switching elements Q11 to Q16 and antiparallel diodes D11 to D16. An IGBT (Insulated Gate Bipolar Transistor) is typically applied as a power semiconductor switching element (hereinafter simply referred to as “semiconductor switching element”), but a power switching element such as a power MOS (Metal Oxide Semiconductor) is used. It is also possible to apply. Similarly, inverter 30-2 is a normal three-phase inverter composed of switching elements Q21 to Q26 and antiparallel diodes D21 to D26.

  U, V and W phases of inverter 30-1 are connected to U phase coil winding U1, V phase coil winding V1 and W phase coil winding W1 of motor generator 34-1, respectively. Similarly, U, V and W phases of inverter 30-2 are connected to U phase coil winding U2, V phase coil winding V2 and W phase coil winding W2 of motor generator 34-2, respectively.

  Electric vehicle 100 further includes a connector 50 for connecting neutral point NP1 of motor generator 34-1 and neutral point NP2 of motor generator 34-2 to external power supply 90, and capacitor C2. That is, electric vehicle 100 is configured to be able to supply AC power input from external power supply 90 (typically commercial power) connected to connector 50 by connector 92 between neutral points NP1 and NP2. Yes. Capacitor C2 is arranged to remove the high-frequency component of the AC voltage supplied from external power supply 90 when connector 50 and connector 92 are connected.

  Therefore, external power supply 90 can be electrically connected to neutral points NP1 and NP2 by connecting connector 50 and connector 92 while electric vehicle 100 is stopped. In this case, power conversion for converting an AC voltage from external power supply 90 into a DC voltage by the reactor components (coil windings) of motor generators 34-1 and 34-2 and inverters 30-1 and 30-2. A vessel is constructed. The converted DC voltage is output between main positive bus MPL and main negative bus MNL, and is used for charging power storage devices 6-1 and 6-2.

  Alternatively, instead of the neutral point charging method as described above, an external charging power converter 95 that converts an AC voltage from the external power supply 90 # into a DC voltage without using the inverters 30-1 and 30-2 is provided. It is good also as a structure provided separately. In that case, AC voltage from external power supply 90 # connected to electrically powered vehicle 100 is removed by high-frequency component by capacitor C2 # by connection of connector 50 # and connector 92 #, and then by power converter 95. Converted to DC voltage. The DC voltage output from power converter 95 between main positive bus MPL and main negative bus MNL is used for charging power storage devices 6-1 and 6-2.

  As described above, electrically powered vehicle 100 according to the present embodiment stores power by supplying power from external power sources 90 and 90 # in addition to charging power storage devices 6-1 and 6-2 by regenerative braking power generation while the vehicle is running. Devices 6-1 and 6-2 can be charged. Hereinafter, such an operation mode in which power storage devices 6-1 and 6-2 are charged by external power supplies 90 and 90 # will be referred to as an “external charging mode”. Generally, the external charging mode is executed for a relatively long time (for example, at night) when the vehicle is parked.

The operation of the power supply system 101 will be described with reference to FIG. 1 again.
Battery ECU 4 estimates the charge levels of secondary batteries 6-1 and 6-2 based on the detection values from voltage sensors 12-1 and 12-2 and current sensors 10-1 and 10-2. Typically, SOC (State of Charge) is estimated as a state quantity indicating a charge level. Here, the SOC indicates a value between 100 (%) indicating the full charge level and 0 (%) indicating the complete discharge level.

  For example, the battery ECU 4 determines whether the secondary battery 6-1 is based on the integration of the current detection value, the open circuit voltage (OCV) estimated from the current detection value and the voltage detection value, or a combination thereof. 6-2 state quantities SOC1 and SOC2 are estimated, and the estimated values are output to converter ECU 2. In addition, it is good also as a structure which performs SOC estimation further using the temperature detection value of the secondary batteries 6-1 and 6-2 by the temperature sensor which is not shown in figure.

  Converter ECU 2 detects detected values from current sensors 10-1 and 10-2 and voltage sensors 12-1, 12-2 and 18, state quantities SOC 1 and SOC 2 from battery ECU 4, and torque target value TR 1 from drive ECU 32. , TR2 and rotation speed target values MRN1, MRN2, drive signals PWC1, PWC2 are generated for driving converters 8-1, 8-2, respectively. Then, converter ECU 2 outputs the generated drive signals PWC1, PWC2 to converters 8-1, 8-2, respectively, to control converters 8-1, 8-2.

Next, the configuration of the power supply system 101 shown in FIG. 1 will be described in detail with reference to FIG.
FIG. 3 is a circuit diagram illustrating in detail the configuration of power supply system 101 according to the embodiment of the present invention shown in FIG.

  Referring to FIG. 3, converter 8-1 includes a chopper circuit 40-1, a positive bus LN1A, a negative bus LN1C, a wiring LN1B, and a smoothing capacitor C01. Chopper circuit 40-1 includes switching elements Q1A and Q1B, diodes D1A and D1B, and an inductor L1.

  Positive bus LN1A has one end connected to the collector of switching element Q1B and the other end connected to main positive bus MPL. Negative bus LN1C has one end connected to negative electrode line NL1 and the other end connected to main negative bus MNL.

  Switching elements Q1A and Q1B are connected in series between negative bus LN1C and positive bus LN1A. Specifically, the emitter of switching element Q1A is connected to negative bus LN1C, and the collector of switching element Q1B is connected to positive bus LN1A. Diodes D1A and D1B are connected in antiparallel to switching elements Q1A and Q1B, respectively. Inductor L1 is connected to a connection point between switching element Q1A and switching element Q1B.

  Line LN1B has one end connected to positive electrode line PL1 and the other end connected to inductor L1. Smoothing capacitor C1 is connected between line LN1B and negative bus LN1C, and reduces the AC component included in the DC voltage between line LN1B and negative bus LN1C.

  Chopper circuit 40-1 operates in accordance with drive signal PWC1 from converter ECU 2 (FIG. 1). The chopper circuit 40-1 basically boosts DC power (drive power) received from the positive line PL1 and the negative line NL1 when the secondary battery 6-1 is discharged, and charges the secondary battery 6-1. The DC power (regenerative power) received from the main positive bus MPL and the main negative bus MNL is stepped down.

  Converter 8-2 includes a chopper circuit 40-2, a positive bus LN2A, a negative bus LN2C, a wiring LN2B, and a smoothing capacitor C02. Chopper circuit 40-2 includes switching elements Q2A and Q2B, diodes D2A and D2B, and an inductor L2. Since the configuration and operation of converter 8-2 are similar to those of converter 8-1, detailed description will not be repeated.

  Further, a relay 7-1 as an “opening / closing device” is provided between the secondary battery 6-1 and the converter 8-1, which is inserted and connected to the positive line PL1 and the negative line NL1. Similarly, a relay 7-2 as an “opening / closing device” is disposed between the secondary battery 6-2 and the converter 8-2, and is connected to the positive line PL2 and the negative line NL2.

  Further, a DC / DC converter 110 for charging an auxiliary battery 120 used for driving a load 130 constituted by an auxiliary machine or ECU is connected to the input side of the converter 8-1. The DC / DC converter 110 is generally configured to be connected to one of a plurality of converters 8-1, 8-2.

  Chopper circuit 40-1 performs bidirectional DC voltage conversion between secondary battery 6-1 and main positive bus MPL and main negative bus MNL in accordance with drive signal PWC1 from converter ECU 2 (FIG. 1). Do. The drive signal PWC1 includes a drive signal PWC1A that controls on / off of the switching element Q1A that is the lower arm element, and a drive signal PWC1B that controls on / off of the switching element Q1B that is the upper arm element. Then, converter ECU 2 controls the duty ratio (on / off period ratio) of switching elements Q1A and / or Q1B within a certain switching cycle (the sum of on period and off period).

  During the boosting operation, converter ECU 2 controls the duty ratio by maintaining upper arm element Q1B (Q2B) in the off state and turning on and off lower arm element Q1A (Q2A) as a basic operation. . Thereby, for example, in converter 8-1, during the ON period of lower arm element Q1A, the discharge current is mainly positive from secondary battery 6-1 through wiring LN1B, inductor L1, diode D1B, and positive bus LN1A in this order. Flows to bus MPL. At the same time, a pump current flows from secondary battery 6-1 through wiring LN1B, inductor L1, lower arm element Q1A, and negative bus LN1C in this order. The inductor L1 accumulates electromagnetic energy by this pump current. When the lower arm element Q1A transitions from the on state to the off state, the inductor L1 superimposes the accumulated electromagnetic energy on the discharge current. As a result, the average voltage of the DC power supplied from converter 8-1 to main positive bus MPL and main negative bus MNL is boosted by a voltage corresponding to the electromagnetic energy stored in inductor L1 according to the duty ratio. During the boost operation, the upper arm elements (Q1B, Q2B) are turned on during the off period of the lower arm elements (Q1A, Q2A) so that the upper arm elements and the lower arm elements are turned on and off in a complementary manner. It is also possible to control each of the converters 8-1, 8-2.

  On the other hand, during the step-down operation, converter ECU 2 maintains, as a basic operation, lower arm element Q1A (Q2A) in the off state and upper arm element Q1B (Q2B) on and off to set its duty ratio. Control. Thus, for example, in converter 8-1, during the on period of upper arm element Q1B, the charging current is secondarily transmitted from main positive bus MPL through positive bus LN1A, upper arm element Q1B, inductor L1, and wiring LN1B in this order. It flows to the battery 6-1. When the upper arm element Q1B transitions from the on state to the off state, the inductor L1 generates a magnetic flux so as to prevent a change in current. Therefore, the charging current continues to flow through the diode D1A, the inductor L1, and the wiring LN1B in this order. . On the other hand, in terms of electrical energy, since the DC power is supplied from the main positive bus MPL and the main negative bus MNL only during the ON period of the upper arm element Q1B, it is assumed that the charging current is kept constant. (Assuming that the inductance of inductor L1 is sufficiently large), the average voltage of DC power supplied from converter 8-1 to secondary battery 6-1 is duty cycle of DC voltage between main positive bus MPL and main negative bus MNL. The value is stepped down according to the ratio. Even during the step-down operation, the lower arm elements (Q1A, Q2A) are turned on during the off period of the upper arm elements (Q1B, Q2B) so that the upper arm elements and the lower arm elements are turned on and off in a complementary manner. It is also possible to control the converters 8-1 and 8-2.

  Similarly, converter 8-2 also receives a bidirectional DC voltage between secondary battery 6-2 and main positive bus MPL and main negative bus MNL in response to drive signal PWC2 from converter ECU 2 (FIG. 1). Perform the conversion. The drive signal PWC2 includes a drive signal PWC2A that controls on / off of the switching element Q2A that is the lower arm element, and a drive signal PWC2B that controls on / off of the switching element Q2B that is the upper arm element. Then, converter ECU 2 controls the duty ratio of switching elements Q2A and / or Q2B within a certain switching period.

  As is well known, in the step-up / step-down chopper circuits 40-1 and 40-2, the boosting operation is emphasized as the ON period ratio of the lower arm elements Q1A and Q2A during the boosting operation increases, and the main positive bus line MPL and the main positive line MPL. The DC voltage Vh between the negative buses MNL increases. In the step-down operation, voltage conversion with a higher voltage ratio Vh / Vb1 (or Vh / Vb2) is performed as the ON period ratio of the upper arm elements Q1B and Q2B decreases (in other words, the OFF period ratio increases). .

  1 to 3, the main positive bus MPL and the main negative bus MNL correspond to “power lines” in the present invention. In addition, switching elements Q1A, Q1B, Q2A, and Q2B constituting converters 8-1 and 8-2 correspond to “a plurality of switching elements” in the present invention, of which upper arm elements Q1B and Q2B are This corresponds to the “first switching element”. Further, the relays 7-1 and 7-2 correspond to the “opening / closing device” in the present invention.

  Converter ECU 2 corresponds to the “control device” in the present invention, and drive ECU 32 corresponds to the “inverter control device” in the present invention. Further, inverters 30-1 and 30-2 correspond to "first inverter" and "second inverter" in the present invention, and motor generators 34-1 and 34-2 correspond to "first inverter" in the present invention. It corresponds to “AC rotating electric machine” and “second AC rotating electric machine”.

  Next, control of converters 8-1, 8-2 (chopper circuits 40-1, 40-2) by converter ECU 2 will be described with reference to FIG.

  FIG. 4 is a functional block diagram illustrating converter control during normal operation by converter ECU 2.

  Referring to FIG. 4, converter ECU 2 includes a target value setting unit 70, a voltage control unit 72-1, and a current control unit 72-2.

  Target value setting unit 70 determines the voltage between main positive bus MPL and main negative bus MNL based on torque target values TR1, TR2 and rotation speed target values MRN1, MRN2 from drive ECU 32, and SOC1, SOC2 from battery ECU 4. A target voltage VR indicating a target value of Vh and a target current IR indicating a target value of the charge / discharge current of the secondary battery 6-2 are generated.

  Voltage control unit 72-1 includes subtraction units 74-1 and 78-1, PI control unit 76-1, and modulation unit 80-1. Subtraction unit 74-1 subtracts voltage Vh from target voltage VR and outputs the calculation result to PI control unit 76-1. The PI control unit 76-1 performs a proportional integration calculation with the deviation between the target voltage VR and the voltage Vh as an input, and outputs the calculation result to the subtraction unit 78-1.

  Calculation unit 78-1 subtracts the output of PI control unit 76-1 from the inverse of the theoretical boost ratio of converter 8-1 indicated by voltage Vb1 / target voltage VR, and uses the calculation result as duty command Ton1 to modulation unit 80. Output to -1. Modulation unit 80-1 generates drive signal PWC1 based on duty command Ton1 and a carrier wave (carrier wave) generated by an oscillation unit (not shown), and outputs the generated drive signal PWC1 to converter 8-1.

  Current control unit 72-2 includes subtraction units 74-2 and 78-2, PI control unit 76-2, and modulation unit 80-2. Subtraction unit 74-2 subtracts current Ib2 from target current IR and outputs the calculation result to PI control unit 76-2. The PI control unit 76-2 performs a proportional integration calculation with the deviation between the target current IR and the current Ib2 as an input, and outputs the calculation result to the subtraction unit 78-2.

  Calculation unit 78-2 subtracts the output of PI control unit 76-2 from the inverse of the theoretical boost ratio of converter 8-2 indicated by voltage Vb2 / target voltage VR, and uses the calculation result as duty command Ton2 for modulation unit 80. Output to -2. Modulation unit 80-2 generates drive signal PWC2 based on duty command Ton2 and a carrier wave (carrier wave) generated by an oscillation unit (not shown), and outputs the generated drive signal PWC2 to converter 8-2.

  Voltage control unit 72-1 increases the on-period ratio of lower arm element Q1A when DC voltage Vh is lower than target voltage VR and when the inverse number of the theoretical boost ratio (Vb1 / VR) decreases ( Alternatively, the drive signal PWC1 is generated so that the off-period ratio of the upper arm element Q1B increases.

  On the other hand, when the output current Ib2 from the secondary battery 6-2 is lower than the target current IR and when the reciprocal of the theoretical boost ratio (Vb2 / VR) is increased, the current control unit 72-2 Drive signal PWC2 is generated so that the ON period ratio of element Q2A increases.

  Note that the current control unit 72-2 charges the secondary battery 6-2, that is, if the target current IR is set to a negative value (IR <0), the current Ib2 (Ib2 < 0) is low (| IR | <| Ib2 |, that is, when the charging current is excessive), the drive signal PWC2 is generated so that the on-period ratio of the upper arm element Q2B decreases. Conversely, when the charging current is insufficient (when IR <Ib2, that is, when | IR |> | Ib2 |), the drive signal PWC2 is generated so that the ON period ratio of the upper arm element Q2B increases.

  Target value setting unit 70 provides torque target values TR1 and TR2 and rotation speed target values of motor generators 34-1 and 34-2 during power running operation and regenerative braking of motor generators 34-1 and / or 34-2. In accordance with MRN1 and MRN2, target voltage VR is set so that DC voltage Vh is at an appropriate level. Furthermore, the target value setting unit 70 sets the target current IR in consideration that the charge level (SOC) between the secondary batteries 6-1 and 6-2 is balanced.

  In normal operation, power supply system 101 performs voltage control of converter 8-1 and current control of converter 8-2 by switching (on / off) operation of upper arm elements Q1B and / or Q2B and lower arm elements Q1A and / or Q2A. The DC voltage Vh and the charge / discharge balance of the secondary batteries 6-1 and 6-2 are controlled.

  Thus, during the power running operation, the electric power discharged from the secondary batteries 6-1 and 6-2 is converted into the voltage Vh as the input voltage of the driving force generation unit 103, and the main positive bus MPL and the main negative bus MNL. The power conversion operation is executed so that the data is output in between. On the other hand, power supply system 101 performs power conversion operation so as to charge secondary batteries 6-1 and 6-2 by charging power on main positive bus MPL and main negative bus MNL during the regenerative braking operation and the external charging mode. Execute.

  However, if the switching operation of the upper arm element and / or the lower arm element is executed in both converters 8-1, 8-2, switching loss occurs in both converters 8-1, 8-2. For this reason, when charging for a long time as in the external charging mode, there is a concern that the efficiency may decrease due to switching loss in converters 8-1 and 8-2.

  Therefore, hereinafter, the control operation in the “efficient charging mode” of converters 8-1 and 8-2, which is suitable for long-time continuous charging as in the external charging mode, will be described. The efficient charging mode corresponds to the “predetermined mode” in the present invention.

  It should be noted that the efficiency charging mode described below is basically applied in the external charging mode, but when a predetermined condition is satisfied during traveling, such as when traveling for a gentle downhill for a long time, It is good also as a structure which applies this efficiency charge mode.

(Efficient charging mode of converter)
FIG. 5 is a conceptual diagram illustrating converter control in the efficient charging mode in the power supply system according to Embodiment 1 of the present invention.

  Referring to FIG. 5, in the power supply system according to Embodiment 1, in the efficient charging mode, one (part) of a plurality of secondary batteries 6-1 and 6-2 is selected as a charging target, and the charging target Other secondary batteries are not charged.

  Then, the converter (charging converter) corresponding to the secondary battery (power storage device) to be charged corresponds to the charging power between the main positive bus MPL and the main negative bus MNL through the execution of the voltage control described in FIG. The secondary battery (power storage device) is charged. On the other hand, in a converter (non-charge converter) corresponding to a secondary battery (power storage device) to be uncharged, gate-off is performed to fix both the upper and lower arm elements off.

  In the illustration of FIG. 5, the secondary battery 6-1 is selected as a charging target, and the corresponding converter 8-1 (charging converter) executes voltage control for controlling the DC voltage Vh to the target voltage VR. And in the ON period of upper arm element Q1B, secondary battery 6-1 is charged. On the other hand, in converter 8-2 (non-charge converter) corresponding to secondary battery 6-2 that is the object of non-charging, both upper arm element Q2B and lower arm element Q2A are fixed off.

  As will be described later, in the power supply system according to the first embodiment, when the secondary battery (power storage device) selected as the charging target is charged to the target level, the charging target is switched. Then, the converter corresponding to the secondary battery (power storage device) selected as the new charge target becomes a new charge converter, and similarly performs charging through voltage control. That is, in the power supply system including the two secondary batteries 6-1 and 6-2, the secondary batteries 6-1 and 6-2 are alternately selected as charging targets.

  FIG. 6 is a functional block diagram illustrating converter control in the efficient charging mode in the power supply system according to the first embodiment.

  Referring to FIG. 6, charge control unit 210 receives a mode signal ECH instructing an efficient charge mode and state quantities SOC1 and SOC2 of secondary batteries 6-1 and 6-2, and selects a charge target. Control signals CT1 and CT2 are generated. The control signal CT1 is turned on when the secondary battery 6-1 is a charging target, and is turned off when the secondary battery 6-1 is a non-charging target. Similarly, the control signal CT2 is turned on when the secondary battery 6-2 is a charging target, and is turned off when the secondary battery 6-2 is a non-charging target.

  Control unit 220 for controlling charging of converter 8-1 is configured to fix voltage control unit 222 configured similarly to voltage control unit 72-1 (FIG. 4) and switching elements Q1A and Q1B to be off. And a gate-off command unit 224. Similarly, control unit 230 for controlling converter 8-2 sets voltage control unit 232 configured similarly to voltage control unit 72-1 (FIG. 4) and switching elements Q2A and Q2B to be off-fixed. Gate-off command unit 234.

  In the efficient charging mode, the target value setting unit 70 sets the target voltage VR for voltage control to a voltage higher than the maximum value of the voltages Vb1 and Vb2 of the secondary batteries 6-1 and 6-2. That is, VR = Max (Vb1, Vb2) + α (α: margin value) is set. As a result, the target voltage VR is set higher than either of the voltages Vb1 and Vb2, so that the target voltage VR is set via the anti-parallel diode (D1B or D2B) connected to the upper arm element (fixed off) of the non-charge converter. The formation of a current path between the secondary batteries 6-1 and 6-2 can be avoided.

  Voltage control unit 222 outputs a drive signal for switching converter 8-1 so as to control voltage Vh to target voltage VR, and voltage control unit 232 controls voltage Vh to target voltage VR. A drive signal for switching the converter 8-2 is output. Gate-off command units 224 and 234 output a driving signal for fixing switching elements Q1A and Q1B to off and a driving signal for fixing switching elements Q2A and Q2B to off, respectively.

  The selector 226 receives the drive signal from each of the voltage control unit 222 and the gate-off command unit 224, generates the drive signal from the voltage control unit 222 as the drive signal PWC1 when the control signal CT1 is on, and when the control signal CT1 is off. The drive signal from the gate-off command unit 224 is output as the drive signal PWC1. Similarly, the selector 236 receives drive signals from the voltage control unit 232 and the gate-off command unit 234, and generates a drive signal from the voltage control unit 232 as the drive signal PWC2 when the control signal CT2 is turned on. When OFF, the drive signal from the gate-off command unit 234 is output as the drive signal PWC2.

  Thereby, as shown in FIG. 5, in the charge converter corresponding to the secondary battery selected as the charge target, at least the upper arm elements (Q1B, Q2B) are provided in order to perform voltage control according to the target voltage VR. While switching, in the non-charge converter, the upper arm element and the lower arm element are fixed off.

  Next, a flow of a series of charging operations in the efficient charging mode in the power supply system according to the first embodiment will be described with reference to FIG. The flowchart shown in FIG. 7 is realized, for example, by executing a predetermined program stored in advance in converter ECU 2.

  Referring to FIG. 7, converter ECU 2 selects a charging target in step S100. For example, the charging target is determined based on the voltages Vb1 and Vb2 of the secondary batteries 6-1 and 6-2. Alternatively, as shown in FIG. 3, in the configuration in which the auxiliary battery 120 is connected to one of the secondary batteries 6-1, the secondary battery (power storage device) to which the auxiliary battery is connected is given priority. It is preferable to select a charging target.

  In step S110, converter ECU 2 starts a charging operation for the charging target selected in step S100. For example, when the secondary battery 6-1 is selected as a charging target and the secondary battery 6-2 is selected as a non-charging target, the converter 8-1 that is a charging converter has the target voltage VR as described above. The voltage control according to this is performed, and gate-off is performed in the non-charge converter (converter 8-2). Thereby, secondary battery 6-1 is charged during the on period of upper arm element Q1B of converter 8-1.

  In step S120, converter ECU 2 determines whether or not the charge level (SOC) to be charged has exceeded the target level (target value). When the secondary battery 6-1 is to be charged, it is determined whether or not the SOC1 exceeds the target value. Then, the charging operation in step S110 is continued until the charge level to be charged exceeds the target level (NO determination in S120).

  On the other hand, when the charge level to be charged exceeds the target level (when YES is determined in S120), converter ECU 2 stops the charging operation in step S110 from step S130. That is, the charge converter (for example, converter 8-1) is also temporarily gated off.

  Further, converter ECU 2 switches the selection of the charging target in step S140. For example, the secondary battery 6-2 is newly charged, and the secondary battery 6-1 that has been charged so far is not charged. The target voltage VR is set similarly to step S110.

  Subsequently, in step S150, converter ECU 2 starts a charging operation for charging secondary battery 6-2 selected as the charging target in step S140. Specifically, the voltage of the converter 8-2 that has become a new charge converter is controlled while the converter 8-1 that has become a new non-charge converter is gated off.

  In step S160, converter ECU 2 determines whether or not the charge level (SOC) to be charged selected in step S140 has exceeded the target level (target value). When secondary battery 6-2 is to be charged, it is determined whether or not SOC2 exceeds the target value. Then, the charging operation in step S150 is continued until the charging level to be charged exceeds the target level (NO determination in S160).

  On the other hand, when the charging level to be charged exceeds the target level (when YES is determined in S160), converter ECU 2 stops the charging operation in step S150 from step S170. That is, the charge converter (for example, converter 8-2) is also gated off, and each converter 8-1, 8-2 is gated off. As a result, a series of processing ends.

  In addition, the target level (SOC target value) about the charge level of charge object in step S120, S160 of FIG. 7 can be set corresponding to a full charge level. Alternatively, assuming that the efficient charging mode is terminated before each secondary battery (power storage device) is charged to the full charge level, the series of processes shown in FIG. 7 is executed a plurality of times. In addition, a control structure may be employed in which each secondary battery (power storage device) is sequentially charged toward the full charge level.

  At this time, the series of processes shown in FIG. 7 is repeatedly executed while gradually updating the target levels in steps S120 and S160. In other words, the target level is set to the full charge level every time the series of processes in FIG. 7 is completed so that each secondary battery (power storage device) is selected as a charge target multiple times before being charged to the full charge level. It is set in such a manner that it gradually rises toward. In this way, even if external charging (efficient charging mode) is terminated before all the secondary batteries 6-1 and 6-2 reach the full charge level, the charge level between the secondary batteries (power storage devices). It is possible to prevent a large difference in (SOC).

  As described above, in the power supply system according to the first embodiment, in the efficient charging mode, only one of converters 8-1, 8-2 is switched to perform charging of the secondary battery (power storage device). The power loss in the converter can be suppressed as compared with the case where each converter is switched and charged in the same manner as in normal operation. For this reason, it is possible to increase the charging efficiency of the power storage device by applying the efficiency charging mode to the external charging mode or the like over a relatively long time.

[Modification of Embodiment 1]
FIG. 8 is a conceptual diagram illustrating the control operation in the efficient charging mode in the power supply system according to the modification of the first embodiment of the present invention.

  In the modification of the first embodiment, the configuration of the power supply system 101 and the electric vehicle 100 on which the power supply system 101 is mounted is the same as that of the first embodiment, and only the converter control in the above-described efficient charging mode is different from the first embodiment.

  Referring to FIG. 8, in the power supply system according to the modification of the first embodiment, the upper arm element and the lower arm element are fixed off in the non-charge converter that is gated off in the efficient charging mode, as in the first embodiment. In other words, it is different from the first embodiment in that the corresponding relay is also turned off. Since other points are the same as those in the first embodiment including the control of the charge converter, detailed description will not be repeated.

  As illustrated in FIG. 8, when the secondary battery 6-1 is an object to be charged, the relay 7 connected between the converter 8-2 that is a non-charge converter and the corresponding secondary battery 6-2. -2 is turned off. On the other hand, when the charging target is switched and the secondary battery 6-2 becomes the charging target, the relay connected between the converter 8-1 serving as a non-charging converter and the secondary battery 6-1. 7-1 is turned off.

  In this manner, the fact that a current path is formed between the secondary batteries 6-1 and 6-2 through the upper arm diode (D1B or D2B) of the non-charged converter that is gated off is physically It becomes possible to prevent.

  FIG. 9 is a flowchart illustrating a series of operations in the efficient charging mode in the power supply system according to the modification of the first embodiment.

  Referring to FIG. 9, in the efficient charging mode according to the modification of the first embodiment, converter ECU 2 executes step S180 after step S100 and step after step S140, compared to the flowchart shown in FIG. The difference is that S190 is further executed. Since the processing in steps S110 to S170 is the same as that in FIG. 7, detailed description will not be repeated.

  When the charging target is selected in step S100, converter ECU 2 turns on the relay corresponding to the charging target and turns off the other relays, that is, the relay corresponding to the non-charging target, in step S180. For example, when secondary battery 6-1 is selected as a charging target in step S100, relay 7-1 is turned on while relay 7-2 is turned off.

  Similarly, when the selection of the charging target is switched at step S140, converter ECU 2 turns on the relay corresponding to the charging target newly selected at step S140 while at step S190, while other relays, that is, until now The relay corresponding to the charging target is also turned off. For example, when secondary battery 6-2 is selected as a charging target instead of secondary battery 6-1, relay 7-1 is turned off while relay 7-2 is turned on in step S190. .

  As described above, in the power supply system according to the modification of the first embodiment, in addition to the effect of the efficient charging mode similar to that of the first embodiment, it is ensured that a short circuit path is generated between the secondary batteries (power storage devices). It becomes possible to prevent.

[Embodiment 2]
Hereinafter, in the second and subsequent embodiments, variations of the efficient charging modes of converters 8-1 and 8-2 in the power supply system having the same configuration as that described in the first embodiment will be sequentially described. Therefore, the configuration and basic operation of power supply system 101 and electric vehicle 100 on which power supply system 101 is mounted are the same as those in the first embodiment, and therefore description thereof will not be repeated. That is, in the second and subsequent embodiments, the control operation in the efficient charging mode of converters 8-1, 8-2 will be described.

  In the second embodiment, an efficient charging mode in which only a part of a plurality of converters is switched and a plurality of power storage devices (secondary batteries) can be charged in parallel will be described.

  FIG. 10 is a conceptual diagram illustrating converter control in the efficient charging mode in the power supply system according to the second embodiment.

  Referring to FIG. 10, in the efficient charging mode of the power supply system according to the second embodiment, secondary battery 6-2 is charged by controlling current of converter 8-2 in which current control is performed during normal operation. As for the remaining converter 8-1, as the non-control converter, the secondary battery 6-1 is charged by fixing the upper arm element Q1B on. That is, in the efficient charging mode according to the second embodiment, secondary batteries 6-1 and 6-2 are charged in parallel.

In this way, in contrast to converter 8-2 (current control converter) in which normal switching operation is performed, in converter 8-1 (non-control converter), the switching element is not turned on / off, so that no switching loss occurs. For this reason, similarly to the first embodiment, power loss in the converter can be suppressed as compared with the case where each converter is charged by switching operation as in the normal operation. Moreover, since the charging current of the secondary battery 6-2 can be controlled by the converter 8-2, the charging level of each secondary battery can also be adjusted.

  FIG. 11 is a functional block diagram illustrating converter control in the efficient charging mode in the power supply system according to the second embodiment.

  Referring to FIG. 11, charging control unit 220 that controls converter 8-1 includes an upper arm on fixing command unit 237. Upper arm on / fixing command unit 237 generates drive signal PWC1 so as to fix upper arm element Q1B to on and to fix lower arm element Q1A to off.

  Control unit 230 for controlling converter 8-2 is configured similarly to current control unit 72-2 (FIG. 4), and performs a switching operation for controlling current Ib2 and voltage Vh according to target current IR and target voltage VR. The drive signal PWC2 is generated as is done.

  In the efficient charging mode according to the second embodiment, target value setting unit 70 sets target voltage VR and target current IR according to voltages Vb1 and Vb2 and state quantities SOC1 and SOC2 of secondary batteries 6-1 and 6-2. Set. The target voltage VR is set to a level equivalent to the higher one of the voltages Vb1 and Vb2.

  Further, target current IR is generated so that SOC1 and SOC2 are equal according to state quantities SOC1 and SOC2. That is, when SOC2 is lower than SOC1, target current IR is set to be relatively high, and when SOC2 is higher than SOC1, target current IR is set to be relatively low. In the external charging mode, the charging power supplied from the external power sources 90 and 90 # constituted by the commercial power source is known. Therefore, by setting the target current IR as described above, the secondary batteries 6-1, 6 are set. -2 can be evenly charged in parallel.

  As a result, as shown in FIG. 10, the secondary batteries 6-1 and 6-2 are charged in parallel by the current control converter that performs current control and the non-control converter in which the upper arm element is turned on. be able to.

  FIG. 12 is a flowchart illustrating a series of operations in the efficient charging mode in the power supply system according to the second embodiment.

  Referring to FIG. 12, converter ECU 2 maintains relays 7-1 and 7-2 at step S 200 when the efficiency charging mode is started. Then, in step S210, based on the state quantities SOC1 and SOC2 of the secondary batteries 6-1 and 6-2, the current control converter (converter 8- 2) Set the target current IR.

  Further, converter ECU 2 starts charging operation by current control converter (converter 8-2) and non-control converter (converter 8-1) in step S220. In step S220, the current control converter charges the secondary battery 6-2 while switching at least the upper arm element Q2B so as to perform current control according to the target current IR. On the other hand, the non-control converter (converter 8-1) fixes the upper arm element Q1B to ON and charges the secondary battery 6-1.

  In step S230, converter ECU 2 determines whether or not the charging level of secondary batteries 6-1 and 6-2 has reached the target level by charging in steps S210 and S220. Specifically, it is determined whether both SOC1 and SOC2 exceed the target value. The charging operation in steps S210 and S220 is continued until both SOC1 and SOC2 reach the target value (NO in S230). At this time, the target current IR is corrected as necessary in step S210 in accordance with the transition of SOC1 and SOC2. Thereby, the secondary batteries 6-1 and 6-2 can be charged equally and in parallel.

  When both SOC1 and SOC2 reach the target values (when YES is determined in S230), converter ECU 2 executes the charge stop process in step S240. Thereby, each converter 8-1 and 8-2 is gated off.

  Thus, in the power supply system according to the second embodiment, in the efficient charging mode, only one of converters 8-1 and 8-2 is switched to perform charging of the secondary battery (power storage device). The power loss in the converter can be suppressed as compared with the case where each converter is switched and charged in the same manner as in normal operation. Furthermore, each secondary battery (power storage device) can be charged in parallel while adjusting the charging power of each secondary battery by current control. Therefore, by applying the efficiency charging mode to the external charging mode or the like over a relatively long time, it is possible to increase the charging efficiency of the power storage device and charge each power storage device equally and in parallel.

[Embodiment 3]
In the third embodiment, an efficient charging mode in which the switching operation is not executed in each converter will be described in order to further suppress power loss due to the converter.

  FIG. 13 is a conceptual diagram illustrating converter control in the efficient charging mode in the power supply system according to the third embodiment.

  Referring to FIG. 13, in the efficient charging mode of the power supply system according to the third embodiment, upper arm elements Q1B, Q2B are fixed on in each of converters 8-1, 8-2, and secondary battery 6- 1,6-2 charging is performed. Thus, both converters 8-1 and 8-2 do not perform an on / off operation (switching operation) on at least one of the lower arm elements of the upper arm element, that is, generate a switching loss associated with the switching operation. Therefore, the secondary batteries 6-1 and 6-2 can be charged.

  However, as shown in FIG. 13, since the upper arm elements Q1B and Q2B are simultaneously turned on by the converters 8-1, 8-2, the charge level difference (voltage difference) between the secondary batteries 6-1 and 6-2. If the SOC difference occurs, a large short-circuit current Isc may occur between the secondary batteries 6-1 and 6-2 at the time of turn-on. Therefore, in the power supply system according to the third embodiment, the charging difference adjustment operation described below is required prior to the start of charging when the upper arm element is turned on.

  FIG. 14 is a functional block diagram illustrating converter control in the efficient charging mode in the power supply system according to the third embodiment.

  Referring to FIG. 14, in Embodiment 3, a charging difference adjustment unit 240 is provided. Charging difference adjustment unit 240 includes a voltage control unit 241 for generating drive signal PWC1 for converter 8-1 and a current control unit 242 for generating drive signal PWC2 for converter 8-2. The voltage control unit 241 is configured in the same manner as the voltage control unit 72-1 illustrated in FIG. 4, and the current control unit 242 is configured in the same manner as the current control unit 72-2 illustrated in FIG. That is, control of converters 8-1 and 8-2 by charge difference adjustment unit 240 is the same as converter control during normal operation.

  Target value setting unit 70 charges between secondary batteries 6-1 and 6-2 based on voltage control unit 241 and voltages Vb1 and Vb2 of secondary batteries 6-1 and 6-2 and state quantities SOC1 and SOC2. The target voltage VR and the target current IR are set so as to cancel the level.

  Upper arm on fixing command unit 244 generates a drive signal PWC1 in converter 8-1 so as to fix upper arm element Q1B to on and to fix lower arm element Q1A to off. Similarly, upper arm on fixing command unit 246 generates drive signal PWC2 in converter 8-2 so as to fix upper arm element Q2B to on and to fix lower arm element Q2A to off.

  The selector 248 receives the set 247a of the drive signals PWC1 and PWC2 generated by the charge difference adjustment unit 240 and the set 247b of the drive signals PWC1 and PWC2 generated by the upper arm on-fixing command units 244 and 246 and charges one of them. The drive signals PWC1 and PWC2 are generated by selecting according to an instruction from the control unit 210.

  Charging control unit 210 receives mode signal ECH instructing start of the efficient charging mode, voltages Vb1 and Vb2 of secondary batteries 6-1 and 6-2, and state quantities SOC1 and SOC2. Then, after the start of the efficient charging mode, when the charge level difference (SOC difference and output voltage difference) between the secondary batteries 6-1 and 6-2 is greater than a predetermined value, the drive signal PWC1 generated by the charge difference adjustment unit 240. , PWC2 is controlled. On the other hand, if the charge level difference between the secondary batteries 6-1 and 6-2 is equal to or less than a predetermined value after the start of the efficient charging mode, the drive signals PWC1 and PWC2 generated by the upper arm on-fixing command units 244 and 246 are selected. Thus, the selector 248 is controlled.

  Thus, as shown in FIG. 13, the charge difference adjustment operation is performed prior to the start of charging, and the upper arm element is fixed on in each converter 8-1, 8-2, and each secondary battery 6- 1,6-2 can be charged.

  FIG. 15 is a flowchart illustrating a series of operations in the efficient charging mode in the power supply system according to the third embodiment.

  Referring to FIG. 15, when the efficiency charging mode is started, converter ECU 2 maintains relays 7-1 and 7-2 on in step S300. Then, through steps S310 and S320, it is determined whether the charge level difference between the secondary batteries 6-1 and 6-2 is equal to or less than a predetermined value. Specifically, in step S310, converter ECU 2 determines whether or not the voltage difference (| Vb1-Vb2 |) between secondary batteries 6-1 and 6-2 is equal to or smaller than a predetermined value. It is determined whether or not the SOC difference between the secondary batteries 6-1 and 6-2, that is, | SOC1-SOC2 |

  Then, when at least one of steps S310 and S320 is NO, converter ECU 2 determines that converter control by charge difference adjustment unit 240 shown in FIG. 10 is necessary. In step S330, in order to adjust the charge level between the secondary batteries 6-1 and 6-2 without starting charging, converter control similar to that during normal operation, that is, the converter 8-1 The voltage control and the current control of the converter 8-2 are continued.

  As described above, at this time, the target voltage VR and the target current IR are generated based on the voltages Vb1, Vb2 and SOC1, SOC2 so as to reduce the charge level difference between the secondary batteries 6-1 and 6-2. Is done. Thus, converters 8-1 and 8-2 can be controlled to charge / discharge secondary batteries 6-1 and 6-2 so that the charge level difference is equal to or less than a predetermined value.

  When both of steps S310 and S320 are determined to be YES, that is, converter ECU 2 determines that the charge level difference between secondary batteries 6-1 and 6-2 is equal to or less than a predetermined value, DC voltage Vh is charged for charging at step S340. Control to level. That is, the target voltage VR is set to a voltage substantially equal to the voltages Vb1 and Vb2, and the converter control similar to that during normal operation is continued. That is, in step S340, the target voltage VR is set to a level equivalent to Max (Vb1, Vb2).

  When it is confirmed in step S340 that voltage Vh has been set to a charging level, that is, a voltage substantially equal to voltages Vb1 and Vb2, converter ECU 2 determines that converters 8-1 and 8-2 By fixing the upper arm elements Q1B and Q2B to ON, charging of the secondary batteries 6-1 and 6-2 is started.

  At this time, since the voltage Vh is controlled to the charging level in advance in step S340, it is possible to prevent an excessive inrush current from occurring when the upper arm elements Q1B and Q2B are turned on.

  In step S360, converter ECU 2 determines whether or not the charging level of secondary batteries 6-1 and 6-2 has reached the target level by charging in step S350. Specifically, it is determined whether SOC1 and / or SOC2 has exceeded a target value. Then, until both SOC1 and / or SOC2 reach the target value (NO determination in S360), the charging operation in step S350 is continued, and the secondary batteries 6-1 and 6-2 are The batteries are charged in parallel through the upper arm elements Q1B and Q2B fixed on.

  Then, converter ECU 2 executes the charge stop process in step S370 when SOC1 and / or SOC2 reaches the target value (when YES is determined in S360).

  In addition, since the charge amount to each secondary battery is not controlled at the time of charging in step S350, there is a charge level difference between the secondary batteries 6-1 and 6-2 when step S360 becomes YES. It may have occurred. Therefore, as part of the charge stop process in step S370, it is preferable to perform final adjustment of the charge level between the secondary batteries 6-1 and 6-2 by the same process as in steps S310 to S330. At the end of the charging stop process, each converter 8-1, 8-2 is gated off.

  Thus, in the power supply system according to the third embodiment, in each of the converters 8-1 and 8-2 in the efficient charging mode, the upper arm element is fixed on and each secondary battery (power storage device) is charged. In each converter, power loss due to switching operation does not occur. For this reason, it is possible to increase the charging efficiency of the power storage device by applying the efficiency charging mode to the external charging mode or the like over a relatively long time.

[Modification of Embodiment 3]
In the modification of the third embodiment, as in the third embodiment, the switching operation in the converter is not executed, and each secondary battery (power storage device) is sequentially charged, so that the charging difference adjustment operation before charging is performed. A description will be given of an efficient charging mode in which no is required.

  FIG. 16 is a conceptual diagram illustrating converter control in the efficient charging mode in the power supply system according to the modification of the third embodiment.

  Referring to FIG. 16, in the efficient charging mode of the power supply system according to the modification of the third embodiment, as in the first embodiment, one of the secondary batteries 6-1 and 6-2 (partially ) Is selected as a charging target, and secondary batteries other than the charging target are not charged. In the converter (charge converter) corresponding to the secondary battery to be charged, the upper arm element is fixed on and the secondary battery is charged. On the other hand, the converter (non-charge converter) corresponding to the secondary battery to be uncharged is gated off, and the upper arm element and the lower arm element are turned off. Furthermore, the relay connected to the non-chargeable secondary battery is also turned off.

  In the example of FIG. 16, since the secondary battery 6-1 is to be charged and the secondary battery 6-2 is not to be charged, the upper arm element Q1B is turned on in the converter 8-1 serving as a charge converter. While being fixed, lower arm element Q1A is fixed off. On the other hand, in converter 8-2, which is a non-charging converter, upper arm elements Q2B and Q2A are fixed off. Further, the relay 7-2 is also turned off.

  Thereby, when the upper arm element is turned on by the charge converter, it is possible to physically prevent a short-circuit current between the secondary batteries 6-1 and 6-2. The charge difference adjustment operation is unnecessary, and the control operation can be simplified.

  FIG. 17 is a functional block diagram illustrating converter control in the efficient charging mode in the power supply system according to the modification of the third embodiment.

  Referring to FIG. 17, charging control unit 210 is configured in the same manner as in FIG. 6, and receives mode signal ECH instructing the efficient charging mode and state quantities SOC1 and SOC2 of secondary batteries 6-1 and 6-2. Thus, control signals CT1 and CT2 for selecting the charging target are generated. That is, which secondary battery is to be charged is selected, and the control signals CT1 and CT2 are selectively turned on based on the selection result.

  Upper arm on fixing command unit 250 generates a drive signal PWC1 in converter 8-1 so as to fix upper arm element Q1B to on and lower arm element Q1A to off, and in converter 8-2, The drive signal PWC2 is generated so that the arm element Q2B is fixed on and the lower arm element Q2A is fixed off.

  Gate off command unit 252 generates drive signal PWC1 in converter 8-1 so as to fix upper arm element Q1B and lower arm element Q1A to off, and in converter 8-2, upper arm element Q2B and lower arm element Q2A. Drive signal PWC2 is generated so as to be fixed to OFF. Furthermore, the gate-off command unit 252 generates a relay-off command for turning off the relay connected to the non-charge target.

  The selector 254 receives a drive signal from each of the upper arm on / fixed command unit 250 and the gate off command unit 252 and generates a drive signal from the upper arm on / fixed command unit 250 as the drive signal PWC1 when the control signal CT1 is on. When CT1 is off, the drive signal from the gate-off command unit 252 is output as the drive signal PWC1. Further, when the control signal CT1 is off, a relay-off command from the gate-off command unit 252 is output to the relay 7-1.

  Similarly, selector 256 receives drive signals from upper arm on / fixed command unit 250 and gate off command unit 252 and generates a drive signal from upper arm on / fixed command unit 250 as drive signal PWC2 when control signal CT2 is on. When the control signal CT2 is off, the drive signal from the gate-off command unit 252 is output as the drive signal PWC2. Further, when the control signal CT2 is turned off, a relay off command from the gate off command unit 252 is output to the relay 7-2.

  Accordingly, as shown in FIG. 16, in the charge converter corresponding to the secondary battery selected as the charge target, the upper arm element is fixed on and the charging operation is performed, whereas in the non-charge converter, the upper arm The element and the lower arm element are fixed off, and the corresponding relay can also be turned off.

  FIG. 18 is a flowchart illustrating a series of operations in the efficient charging mode in the power supply system according to the modification of the third embodiment.

  Referring to FIG. 18, converter ECU 2 selects a secondary battery (power storage device) to be charged in step S400 by the same processing as S100 in FIG. 9. In step S410, the relay corresponding to the charging target is turned on, and the other relays, that is, the relay corresponding to the non-charging target is turned off. For example, when secondary battery 6-1 is selected as a charging target in step S400, relay 7-1 is turned on while relay 7-2 is turned off.

  Further, converter ECU 2 starts a charging operation to the charging object selected in step S400 in step S420. At this time, in the charge converter (converter 8-1), the upper arm element is fixed to ON, and in the other non-charge converters (converter 8-2), the gate is turned off, that is, each switching element is fixed to OFF.

  Then, in step S430, converter ECU 2 determines whether or not the charge level (SOC) to be charged has exceeded the target level (target value). When the secondary battery 6-1 is to be charged, it is determined whether or not the SOC1 exceeds the target value. Then, until the charging level to be charged exceeds the target level (NO determination in S430), the charging operation in step S420 is continued.

  On the other hand, when the charge level to be charged exceeds the target level (when YES is determined in S430), converter ECU 2 stops the charging operation in step S420 from step S440. That is, the charge converter (for example, converter 8-1) is also temporarily gated off.

  Then, converter ECU 2 switches the selection of the charging target in step S450. For example, the secondary battery 6-2 is newly charged, and the secondary battery 6-1 that has been charged so far is not charged. Further, in step S460, the relay corresponding to the charging object newly selected in step S450 is turned on, while the other relays, that is, the relays corresponding to the charging objects so far are also turned off. For example, when secondary battery 6-2 is selected as a charging target in step S450, relay 7-2 is turned on while relay 7-1 is turned off.

  Further, converter ECU 2 starts a charging operation for charging secondary battery 6-2 selected as the charging target in step S450 in step S470. Specifically, the upper arm element is fixed on in the charge converter (converter 8-2), and the gate off, that is, each switching element is fixed off in the other non-charge converters (converter 8-1).

  In step S480, converter ECU 2 determines whether or not the charge level (SOC) to be charged selected in step S450 has exceeded the target level (target value). When secondary battery 6-2 is to be charged, it is determined whether or not SOC2 exceeds the target value. Then, until the charging level to be charged exceeds the target level (NO determination in S480), the charging operation in step S470 is continued.

  On the other hand, when the charge level to be charged exceeds the target level (when YES is determined in S480), converter ECU 2 stops the charging operation in step S470 from step S490. That is, the charge converter (for example, converter 8-2) is also gated off. As a result, a series of processing ends.

  Even in the modification of the third embodiment, since each secondary battery (power storage device) is sequentially selected and charged, the efficient charging mode is terminated before each secondary battery reaches the full charge level. In order to cope with this, it is preferable to set the charging target levels in steps S430 and S480 in the same manner as in steps S120 and S160 in FIG. That is, it is preferable that the control operation according to FIG. 18 is repeatedly performed a plurality of times.

  As described above, in the efficient charging mode of the power supply system according to the modification of the third embodiment, similarly to the third embodiment, the converters 8-1 and 8-2 do not perform the switching operation, that is, the switching element loss. The secondary batteries 6-1 and 6-2 can be charged without generating the above.

  Further, since the gate is turned off by the non-charge converter and the corresponding relay is turned off, it is possible to reliably prevent a short-circuit current from being generated between the secondary batteries 6-1 and 6-2 at the start of charging. Therefore, the charge difference adjusting operation before charging as in the third embodiment is not necessary, and the control operation can be simplified.

  In the first to third embodiments and the modifications thereof described above, two secondary batteries (power storage devices) 6-1 and 6-2, and converters 8-1 and 8-2 corresponding to the respective batteries are provided. However, the application of the present invention is not limited to such a configuration.

  That is, as shown in FIG. 19, even in a power supply system having a configuration in which a plurality of power storage devices (secondary batteries) and corresponding converters are provided in three or more, efficient charging according to the first to third embodiments and their modifications Mode can be applied.

  In the power supply system having such a configuration, the converters 8-3,... For the secondary batteries 6-3,. , 8-2, the efficient charging mode according to the first to third embodiments and their modifications can be applied. For example, in each of the secondary batteries (power storage devices) that are sequentially selected as charging targets, in Embodiment 1 and its modification example and in the modification example of Embodiment 3, each of converters 8-3,. It is sequentially controlled as a charge converter or a non-charge converter according to the selection of the object. In the second and third embodiments in which the secondary batteries (power storage devices) are charged in parallel, each of converters 8-3,... Is controlled in the same manner as one of converters 8-1, 8-2. .

  In each of the above embodiments, the electric vehicle 100 generates electric energy using a hybrid vehicle equipped with an internal combustion engine that generates kinetic energy using fuel, an electric vehicle not equipped with an internal combustion engine, and fuel. It may be a fuel cell vehicle further equipped with a fuel cell.

  Note that, in the above, each control in converter ECU 2 and battery ECU 4 is actually executed by a CPU (Central Processing Unit), and CPU executes a program including each step of the flowchart described in each embodiment in ROM (Read (Only Memory), the read program is executed, and the process is executed according to the flowchart. Therefore, the ROM corresponds to a computer (CPU) readable recording medium in which a program including each step of the flowchart described in each embodiment is recorded.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is an overall block diagram of an electric vehicle equipped with a power supply system according to an embodiment of the present invention. FIG. 2 is a circuit diagram illustrating in detail a configuration of a driving force generation unit illustrated in FIG. 1. It is a circuit diagram explaining the structure of the power supply system shown in FIG. 1 in detail. It is a functional block diagram explaining converter control at the time of normal operation by converter ECU. 3 is a conceptual diagram illustrating converter control in an efficient charging mode in the power supply system according to Embodiment 1. FIG. 3 is a functional block diagram illustrating converter control in an efficient charging mode in the power supply system according to Embodiment 1. FIG. 3 is a flowchart illustrating a series of operations in an efficient charging mode in the power supply system according to the first embodiment. It is a conceptual diagram explaining the converter control in the efficient charge mode in the power supply system by the modification of Embodiment 1. FIG. 6 is a flowchart illustrating a series of operations in an efficient charging mode in a power supply system according to a modification of the first embodiment. 6 is a conceptual diagram illustrating converter control in an efficient charging mode in the power supply system according to Embodiment 2. FIG. 10 is a functional block diagram illustrating converter control in an efficient charging mode in the power supply system according to Embodiment 2. FIG. 6 is a flowchart illustrating a series of operations in an efficient charging mode in the power supply system according to the second embodiment. 10 is a conceptual diagram illustrating converter control in an efficient charging mode in the power supply system according to Embodiment 3. FIG. 10 is a functional block diagram illustrating converter control in an efficient charging mode in the power supply system according to Embodiment 3. FIG. 10 is a flowchart illustrating a series of operations in an efficient charging mode in the power supply system according to the third embodiment. FIG. 11 is a conceptual diagram illustrating converter control in an efficient charging mode in a power supply system according to a modification of the third embodiment. 12 is a functional block diagram illustrating converter control in an efficient charging mode in a power supply system according to a modification of the third embodiment. FIG. 10 is a flowchart illustrating a series of operations in an efficient charging mode in a power supply system according to a modification of the third embodiment. It is a block diagram which shows the modification of a structure of a power supply system.

Explanation of symbols

  2 Converter ECU, 4 Battery ECU, 6-1, 6-2, 6-3 Secondary battery (power storage device), 7-1, 7-2 Relay (opening / closing device), 8-1, 8-2, 8- 3 Converter, 10-1, 10-2 Current sensor, 12-1, 12-2 Voltage sensor, 18 Voltage sensor, 30-1, 30-2 Inverter, 32 Drive ECU, 34-1 (MG1), 34-2 (MG2) Motor generator, 36 power transmission mechanism, 38 drive shaft, 40-1, 40-2 chopper circuit, 50, 92 connector, 70 target value setting unit, 72-1, 232, 241, 222 voltage control unit, 72 -2, 242 Current control unit, 74-1, 74-2, 78-1, 78-2 Subtraction unit, 76-1, 76-2 PI control unit, 78-1, 78-2 arithmetic unit, 80-1 , 80-2 modulator, 90, 90 External power supply, 95 Power converter (for charging), 100 Electric vehicle, 101 Power supply system, 103 Driving force generator, 110 DC / DC converter (auxiliary), 120 Auxiliary battery, 130 Load, 210 Charging controller, 220 , 230 control unit, 224, 234, 252 gate off command unit, 226, 236, 248, 254, 256 selector, 237, 244, 246, 250 upper arm on fixing command unit, 240 charge difference adjustment unit, 247a, 247b drive signal, C01, C02, C1 Smoothing capacitor, C2 capacitor, CT1, CT2 control signal, D11-D16, D1A, D1B, D21-D26 Anti-parallel diode, ECH mode signal (efficiency charging mode), Ib1, Ib2 current (secondary battery) , IR target current (current control), Isc short circuit Current, L1, L2 inductor, LN1A, LN2A positive bus, LN1B, LN2B wiring, LN1C, LN2C negative bus, MNL main negative bus, MPL main positive bus, MRN1, MRN2 target number of rotations (motor generator), NL1, NL2 negative Wire, NP1, NP2 neutral point, PL1, PL2 positive line, PWC1, PWC1A, PWC1B, PWC2, PWC2A, PWC2B drive signal (converter), PWM1, PWM2 drive signal (inverter), Q11-Q16, Q21-Q26 For power Semiconductor switching element (inverter), Q1A, Q2A Power semiconductor switching element (converter lower arm element), Q1B, Q1B Power semiconductor switching element (converter upper arm element), SOC1, SOC2 State quantity (charge level), To 1, Ton2 duty command, TR1, TR2 torque target value (motor generator), U1, U2 U phase coil winding, V1, V2 V phase coil winding, Vb1, Vb2 voltage (secondary battery), Vh DC voltage, VR Target voltage (voltage control), W1, W2 W-phase coil winding.

Claims (24)

A power supply system mounted on an electric vehicle capable of generating a driving force using electric power on a power line,
A plurality of chargeable / dischargeable power storage devices;
A plurality of power lines connected to the power line and the plurality of power storage devices, each for performing bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and the power line; A plurality of converters configured to include a power semiconductor switching element;
A control device for controlling on and off of each power semiconductor switching element of each of the converters,
The plurality of power semiconductor switching elements includes a first switching element electrically connected between the power line and the corresponding power storage device,
The control device selects at least a part of the plurality of power storage devices as a charging target in the predetermined mode in which the plurality of power storage devices are charged with power supplied to the power line, and the charging target In the converter corresponding to the power storage device selected in the above, the first switching element is fixed on without controlling the voltage of the power line and the charging current of the selected power storage device, while other than the charging target In the converter corresponding to the remaining power storage devices, the power supply system charges the plurality of power storage devices by fixing the first switching element to OFF. The control device, in the predetermined mode, after selecting each of the plurality of power storage devices to be charged in parallel and performing an adjustment operation for preventing inrush current between the power storage devices at the start of charging, The power supply system according to claim 1, wherein the first switching element is fixed on in each of the converters. In the predetermined mode, the control device is configured to adjust the voltage of the power line by performing on / off control of at least one of the plurality of power semiconductor switching elements by at least one of the plurality of converters as the adjustment operation. 3. The power supply system according to claim 2, wherein the first switching element is fixed on in each of the converters after being controlled to be equal to the highest voltage among the output voltages of the power storage device. When the charge level difference between the plurality of power storage devices is greater than a predetermined value at the start of the predetermined mode, the control device performs the adjustment operation so that the charge level difference is equal to or less than the predetermined value. wherein after Gyoshi plurality of converter control, fixed to turn on the first switching element in each said converter, claim 2 power supply system according to which the power storage device is charged and discharged. A plurality of opening and closing devices respectively provided between the plurality of converters and the plurality of power storage devices;
In the predetermined mode, the control device sequentially selects a part of the plurality of power storage devices as a charging target and the first converter in the converter corresponding to the power storage device selected as the charging target. 2. The power supply system according to claim 1, wherein the first switching element corresponding to the remaining power storage device other than the charging target is fixed off and the switchgear is turned off while the switching element is fixed on. . A power supply system mounted on an electric vehicle capable of generating a driving force using electric power on a power line,
A plurality of chargeable / dischargeable power storage devices;
A plurality of power lines connected to the power line and the plurality of power storage devices, each for performing bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and the power line; A plurality of converters configured to include a power semiconductor switching element;
A control device for controlling on and off of each power semiconductor switching element of each of the converters,
The plurality of power semiconductor switching elements includes a first switching element electrically connected between the power line and the corresponding power storage device,
In the converter corresponding to a part of the plurality of power storage devices in the predetermined mode in which the control device charges the plurality of power storage devices with power supplied to the power line, the corresponding power storage device In the converter corresponding to the remaining power storage devices other than the part of the power storage devices, voltage control is performed while turning on / off at least one of the plurality of power semiconductor switching elements so as to control the charging current of the power supply to a target current. And a power supply system that charges the plurality of power storage devices by fixing the first switching element to ON without performing current control .   The power supply system according to claim 6, wherein the control device sets the target current according to a difference in charge level between the plurality of power storage devices. A power supply system mounted on an electric vehicle capable of generating a driving force using electric power on a power line,
A plurality of chargeable / dischargeable power storage devices;
A plurality of power lines connected to the power line and the plurality of power storage devices, each for performing bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and the power line; A plurality of converters configured to include a power semiconductor switching element;
A plurality of switching devices respectively provided between the plurality of converters and the plurality of power storage devices;
A control device for controlling on and off of each power semiconductor switching element of each of the converters,
The plurality of power semiconductor switching elements includes a first switching element electrically connected between the power line and the corresponding power storage device,
The control device sequentially selects a part of the plurality of power storage devices as a charging target in a predetermined mode in which the plurality of power storage devices are charged with power supplied to the power line, and the charging target In the converter corresponding to the power storage device selected in the step, at least one of the plurality of power semiconductor switching elements is turned on / off so as to control the voltage of the power line to a target voltage, In the converter corresponding to the power storage device, the plurality of power storage devices are charged by fixing the first switching element to be off ,
The said control apparatus is a power supply system which turns off each said switching apparatus corresponding to electrical storage apparatuses other than the said charging object in the said predetermined mode .   The power supply system according to claim 8, wherein the control device sets the target voltage to be higher than a maximum voltage among output voltages of the plurality of power storage devices. The control device switches the selection of the charging target in response to the charging of the power storage device to be charged to a target level,
The power supply system according to claim 5 or 8, wherein the target level is set so as to be selected as the charging target a plurality of times before each power storage device is charged to a full charge level. The power supply system according to any one of claims 1 to 10 , wherein in the predetermined mode, power from an external power supply of the electric vehicle is supplied to the power line. The power supply system according to any one of claims 1 to 11 ,
A first AC rotating electric machine including a first multiphase winding connected in a star shape as a stator winding;
A second AC rotating electric machine including a second multiphase winding connected in a star shape as a stator winding;
A first inverter connected to the first multiphase winding and performing power conversion between the first AC rotating electric machine and the power line;
A second inverter connected to the second multiphase winding and performing power conversion between the second AC rotating electric machine and the power line;
In the predetermined mode, electrical connection is made between the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding and an AC power supply outside the electric vehicle. A connector part for connection
An inverter control device for controlling on and off of the power semiconductor switching elements of the first and second inverters;
At least one of the first and second AC rotating electric machines is used to generate the traveling driving force,
In the predetermined mode, the inverter control device converts an AC voltage from the AC power source supplied to the first and second neutral points via the connector portion into a DC voltage and converts the AC voltage to the power line. An electric vehicle that controls each of the first and second inverters to output. A control method for a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line,
The power supply system includes:
A plurality of chargeable / dischargeable power storage devices;
A plurality of power lines connected to the power line and the plurality of power storage devices, each for performing bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and the power line; A plurality of converters configured to include a power semiconductor switching element;
A control device for controlling on and off of each power semiconductor switching element of each of the converters,
The plurality of power semiconductor switching elements includes a first switching element electrically connected between the power line and the corresponding power storage device,
The control method is:
Selecting at least some of the plurality of power storage devices as charging targets in a predetermined mode in which the plurality of power storage devices are charged with power supplied to the power line; and
In the converter corresponding to the power storage device selected as the charging target, the first switching element is fixed on, while in the converter corresponding to the remaining power storage device other than the charging target, voltage control and current And performing a charging operation by fixing the first switching element to OFF without performing control. In the predetermined mode, the selecting step selects each of the plurality of power storage devices to be charged in parallel,
The control method is:
Prior to the charging operation, further comprising the step of performing an adjustment operation for preventing inrush current between the plurality of power storage devices at the start of charging,
The method of controlling a power supply system according to claim 13 , wherein the step of executing the charging operation fixes the first switching element to ON in each of the converters after the adjustment operation . The step of executing the adjusting operation is performed by controlling at least one of the plurality of power semiconductor switching elements by at least one of the plurality of converters to control the voltage of the power line to the output voltage of the plurality of power storage devices. The method of controlling a power supply system according to claim 14 , comprising the step of controlling the voltage to be equal to the highest voltage. The step of performing the adjusting operation includes the step of charging and discharging the plurality of power storage devices so that the charge level difference is equal to or less than the predetermined when the charge level difference between the plurality of power storage devices is greater than a predetermined value. The method of controlling a power supply system according to claim 14 , comprising controlling a plurality of converters. The power supply system includes:
A plurality of switching devices provided respectively between the plurality of converters and the plurality of power storage devices;
The selecting step sequentially selects a part of the plurality of power storage devices as a charging target in the predetermined mode,
The step of executing the charging operation corresponds to the remaining power storage devices other than the charging target while fixing the first switching element on in the converter corresponding to the power storage device selected as the charging target. The method of controlling a power supply system according to claim 13 , wherein the first switching element is fixed off and the switchgear is turned off. A control method for a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line,
The power supply system includes:
A plurality of chargeable / dischargeable power storage devices;
A plurality of power lines connected to the power line and the plurality of power storage devices, each for performing bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and the power line; A plurality of converters configured to include a power semiconductor switching element;
A control device for controlling on and off of each power semiconductor switching element of each of the converters,
The plurality of power semiconductor switching elements includes a first switching element electrically connected between the power line and the corresponding power storage device,
The control method is:
In a predetermined mode in which the plurality of power storage devices are charged with the power supplied to the power line, a charging current of the corresponding power storage device is targeted in the converter corresponding to a part of the plurality of power storage devices. While at least one of the plurality of power semiconductor switching elements is turned on / off so as to be controlled by current , voltage control and current control are performed in the converter corresponding to the remaining power storage devices other than the part of the power storage devices A control method for a power supply system, comprising the step of performing a charging operation by fixing the first switching element to ON without the first switching element. The control method of the power supply system according to claim 18 , further comprising the step of setting the target current in the charging operation according to a difference in charge level between the plurality of power storage devices. A control method for a power supply system mounted on an electric vehicle capable of generating travel driving force using electric power on a power line,
The power supply system includes:
A plurality of chargeable / dischargeable power storage devices;
A plurality of power lines connected to the power line and the plurality of power storage devices, each for performing bidirectional power conversion between a corresponding power storage device of the plurality of power storage devices and the power line; A plurality of converters configured to include a power semiconductor switching element;
A plurality of switching devices respectively provided between the plurality of converters and the plurality of power storage devices;
A control device for controlling on and off of each power semiconductor switching element of each of the converters,
The plurality of power semiconductor switching elements includes a first switching element electrically connected between the power line and the corresponding power storage device,
The control method is:
Sequentially selecting a part of the plurality of power storage devices as a charging target in a predetermined mode in which the plurality of power storage devices are charged with power supplied to the power line; and
In the converter corresponding to the power storage device selected as the charging target, at least one of the plurality of power semiconductor switching elements is turned on / off so as to control the voltage of the power line to a target voltage, while other than the charging target In the converter corresponding to the remaining power storage device, performing a charging operation by fixing at least the first switching element off ; and
And a step of opening the switchgear corresponding to the remaining power storage device prior to performing the charging operation . 21. The method of controlling a power supply system according to claim 20 , wherein in the step of executing the charging operation, the target voltage is set to be higher than a maximum voltage among output voltages of the plurality of power storage devices. Detecting that the power storage device to be charged has been charged to a target level;
Further comprising the step of switching the selection of the charging object in response to detection in the detecting step,
The power supply system according to claim 17 or 20 , wherein, in the detecting step, the target level is set to be selected as the charging target a plurality of times until each power storage device is charged to a full charge level. Control method. The method for controlling a power supply system according to any one of claims 13 to 22 , wherein in the predetermined mode, electric power from an external power supply of the electric vehicle is supplied to the power line. The electric vehicle is
A first AC rotating electric machine including a first multiphase winding connected in a star shape as a stator winding;
A second AC rotating electric machine including a second multiphase winding connected in a star shape as a stator winding;
A first inverter connected to the first multiphase winding and performing power conversion between the first AC rotating electric machine and the power line;
A second inverter connected to the second multiphase winding and performing power conversion between the second AC rotating electric machine and the power line;
In the predetermined mode, between the first neutral point of the first multiphase winding and the second neutral point of the second multiphase winding and the AC power supply outside the electric vehicle. A connector part for electrical connection;
An inverter control device for controlling on and off of the power semiconductor switching elements of the first and second inverters;
At least one of the first and second AC rotating electric machines is used to generate the traveling driving force,
In the predetermined mode, the inverter control device converts an AC voltage from the AC power source supplied to the first and second neutral points via the connector portion into a DC voltage and converts the AC voltage to the power line. The method for controlling a power supply system according to any one of claims 13 to 23 , wherein each of the first and second inverters is controlled so as to be output.

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